The plates of the interiors of the sections, all shown as seen from the
east, carry for the most part their own explanations, yet the following
additional notes may be serviceable to any reader unfamiliar with similar
work. At the top the horizontal line is the datum from which all the
vertical measurements are calculated, and the figures along it record in feet,
with decimal fractions, its height at various points above (1) the undisturbed
ground, (2) the kerbing of the vallum, (3) the black lines in the soil,
(4) the bottom of the cutting made, or (5) the layers of soil (as in Seabeg
section No. 2) in the outer mound. -These successive measurements readily
enable any desired dimension to be ascertained. For ease of reference the
datum line in every section has been fixed at 10 feet above the level of the
south kerb. The bottom series of figures records the horizontal distances,
north and south respectively, from the kerbs of the vallum.